The invention relates in general to a wood-working tool, in particular, to a self-actuated high precision chisel.
Self-actuated tools of this type typically consist of a reciprocating shaft and a weighted handle which may incorporate a spring. Such tools typically are impartial as to the rotational orientation of the cutting edge in relation to the handle and therefore provide no means of controlling such orientation as in U.S. Pat. No. 1,435,866 issued to McGahey. Still other such tools imprecisely impart a fixed orientation as between handle and working surface by means of a pin and slot configuration as taught by Hamilton, Jr. U.S. Pat. No. 2,485,877. This method of controlling orientation is imprecise due to the loose fit and limited contact between pin and slot. This means is also cumbersome in that there is relative movement outside the guide sleeve resulting in potential for pinch, and is inexact in that the orientation greatly depends on the visual placement by the user of the orientation of the cutting edge.
Therefore, it is an object of the present invention to impart exact orientation of the cutting edge by means of a configured haft which has a precisely fitted relationship to a reciprocal tool shank, and wherein the shank carries precision guide means for low-friction axially precise sliding inter-relationship with the walls of chamber within the haft to prevent angular misalignment.
It is also an object of this invention to provide such a tool which may be used both as a self-actuated woodworking tool and a conventional chisel as it might be struck on the cutting edge-remote end with a mallet to impart force to the cutting edge.
A still further object of the invention is to provide such a tool having a precision crafted chambered haft configured such that the orientation of the cutting edge is accurately perceived by the user merely by tactile sensation communicated via the haft/tool shank relationship.
Another object of the invention is the provision of such a tool which includes a kick-back spring for assisting in the self-actuated mode of usage.
Further objects of the invention will be apparent from a continued reading below.